| From | Ming Lei <> | Subject | [PATCH v3 26/49] block: introduce bvec_for_each_sp_bvec() | Date | Tue, 8 Aug 2017 16:45:25 +0800 |
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This helper can be used to iterate each singlepage bvec from one multipage bvec.
Signed-off-by: Ming Lei <ming.lei@redhat.com> --- include/linux/bvec.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/include/linux/bvec.h b/include/linux/bvec.h index c1ec0945451a..23d3abdf057c 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -224,4 +224,18 @@ static inline bool bvec_iter_advance_mp(const struct bio_vec *bv, .bi_bvec_done = 0, \ } +/* + * This helper iterates over the multipage bvec of @mp_bvec and + * returns each singlepage bvec via @sp_bvl. + */ +#define __bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter, start) \ + for (iter = start, \ + (iter).bi_size = (mp_bvec)->bv_len - (iter).bi_bvec_done; \ + (iter).bi_size && \ + ((sp_bvl = bvec_iter_bvec((mp_bvec), (iter))), 1); \ + bvec_iter_advance((mp_bvec), &(iter), (sp_bvl).bv_len)) + +#define bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter) \ + __bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter, BVEC_ITER_ALL_INIT) + #endif /* __LINUX_BVEC_ITER_H */ -- 2.9.4
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